添加剂作用下铝酸钠溶液物化性质的变化对产品性能的影响

在铝酸钠溶液的晶种分解过程中,加入适当的添加剂--表面活性剂,可以强化铝酸钠溶液的晶种分解过程,提高产品氢氧化铝的强度、粒度和分解率.选用8种添加剂,100mg/L和200mg/L两种添加量做分解试验,对加入不同类型添加剂的铝酸钠溶液的表面张力、粘度、电导率进行了测试,考察了添加剂的加入量对铝酸钠溶液物理化学性质的影响.结果表明:添加剂C、E2、F可以提高铝酸钠溶液的分解率,并能增大产品氢氧化铝的粒度与强度;添加剂的加入使铝酸钠溶液的表面张力降低0.015～0.020N/m时,析出的氢氧化铝的粒度与强度较好;能使氢氧化铝粒度增大、强度提高的添加剂,均使铝酸钠溶液的粘度有所下降.     

氢氧化铝的晶型结构对氧化铝强度的影响

氧化铝的强度与氢氧化铝颗粒独特的显微形貌有着内在的联系,而氢氧化铝颗粒的显微形貌取决于铝酸钠溶液的分解工艺。氧化铝与氢氧化铝颗粒的显微形貌相似,通过跟踪监测流程中分解产物氢氧化铝颗粒的显微形貌来合理调整分解工艺,对得到强度较好的氧化铝产品有着重要的指导意义。     

铝酸钠溶液种分过程中草酸钠结晶析出的行为

拜耳法氧化铝生产过程中,草酸钠在铝酸钠溶液晶种分解工序造成诸多负面影响.本文对种分过程草酸钠结晶析出的行为进行研究.用含草酸钠的合成和工业铝酸钠溶液分别进行分解实验,考察草酸钠对分解产物粒度和形貌的影响,并对草酸钠的结晶习性、草酸钠与氢氧化铝之间的相互作用规律进行探究.结果表明,草酸钠在氢氧化铝表面或颗粒间隙结晶析出,使氢氧化铝二次成核增加,并严重阻碍氢氧化铝的附聚,这是其造成产品氢氧化铝粒度细化的主要原因.      

新技术与新成果

200308超细氢氧化铝的制备方法本发明(CN1258639A)为一种超细氢氧化铝的制备方法。由在旋转床超策略条件下的碳分分解和水热处理两道工序组成,本发明的碳分分解反应在旋转床的多孔填料层中进行,极大地强化了反应的传质及微观混合过程,随后的水热处理过程使得到的氢氧化铝凝胶进一步转化为晶体颗粒。此法有效地克服了现在技术中晶粒难以细化、粒度分布不均匀、反应时间长等缺点,得到的氢氧化铝颗粒呈纤维状,其平均粒径可小至1～5mm,长径比达5～100,且粒径分布均匀,大幅度地提高了生产效率及产品品位。本发明的方法易于工业化生产。200309用…     

磷酸钠对铝酸钠溶液晶种分解的影响

研究了磷酸盐杂质对铝酸钠溶液晶种分解的影响,并探讨了其影响机理.结果表明,在浓度小于5g/L时,磷酸盐能提高铝酸钠溶液的分解率,使晶种分解产品的粒度增大.磷酸盐杂质的存在不会显著影响铝酸钠溶液中氢氧化铝颗粒表面的Zeta电位值,但是会使铝酸钠溶液表面张力增大.     

一水硬铝石拜耳法生产砂状氧化铝的分解与分级

<正> 目前,砂状氧化铝生产采用的分解工艺流程主要有:Ⅰ段连续、间断分解;Ⅱ段双系列连续分解,以及Ⅱ段混联连续分解。分解仍用下列三种传统方法:1,基于粒子长大的分解方法,把较粗颗粒的氢氧化铝种子加入到精液中使粒子长大;2,基于粒子附聚长大的分解方法,把细颗粒氢氧化铝种     

拜耳法碳分制备粗粒氢氧化铝工艺研究

采用碳酸氢钠溶液分解拜耳法精液制备粗粒氢氧化铝,研究了分解温度、分解时间、分解制度、分解深度、碳酸氢钠溶液浓度及晶种对氢氧化铝产品粒度的影响,在适当的工艺条件下,所得第一段产品<45μm粒子质量分数可降至9.94%。     

种分氢氧化铝作碳分活性晶种的工艺探索

种分过程存在产品周期性细化的现象，为了缓和种分氢氧化铝粒度波动，将种分氢氧化铝加入碳分流程。通过各种试验证明，碳分流程可以很好地消化种分细料，从而控制产品氢氧化铝中的极细颗粒。     

制取超细氢氧化铝阻燃剂的研究

利用重溶法对氢氧化铝精液进行除杂净化,控制精液的αk为1.3 ～1.5,加入研磨好的氢氧化铝晶种（D50为1～2μm）,晶种系数为10％ ～ 12％,分解温度控制在60℃,分解时间为24 h,可以得到D50为1～2 μm、白度为97的超细氢氧化铝阻燃剂.经检验证明,试验产品能达到国家生产标准.     

浅析铝酸钠分解工序晶粒附聚

分解工序是拜耳法生产氧化铝的关键环节,铝酸钠溶液在分解工序的作业效果对产品的质量和产量以及经济指标有着重大的影响,在分解工序除了晶体自身的长大之外在一定的搅拌下溶液中直径小于20μm的颗粒也会附聚在直径较大的颗粒上,晶体自身的长大与晶粒的附聚共同作用使氢氧化铝的结晶变粗,本文结合生产实际情况对分解工序的晶粒附聚进行了介绍分析。     

有机溶剂分离法处理废旧锂离子电池

针对现有废旧锂电池回收钴金属工艺中铝钴分离的问题,采用特定的有机溶剂分离法,使锂电池正极材料中的钴酸锂从铝箔上溶解下来,直接分离钴酸锂和铝箔,铝箔经清洗后直接回收,所用的有机溶剂通过蒸馏方式脱除粘结剂,实现循环使用。该工艺简化废旧锂电池正极材料的回收处理工艺流程,有效地回收钴与铝。     

Physicochemical properties of the alumina produced by alkaline and acidic methods

Crystal-optical, X-ray diffraction, and thermogravimetric methods are used to study the polymorphic transformations in the products of calcination of the aluminum hydroxide produced by the decomposition and carbonization of aluminate solutions; the aluminum oxide produced by the decomposition of pure grade crystal hydrates of aluminum salts; and the alumina extracted upon the beneficiation of the mineral part of coaly rock with sulfuric, hydrochloric, and nitric acids. The morphology of the products of the thermal decomposition of the initial compounds is examined. The effect of impurities and a reducing agent on the formation of the structural modifications of alumina during heat treatment is revealed.     

从高氟硫酸铍溶液中萃取铍工艺研究

高氟铍矿石中的成分复杂,其中氟、磷、硅、铝、铁等杂质在传统法工艺中对氧化铍的回收率及质量影响很大;萃取法生产氧化铍过程中,P204对铍浸出液中的阳离子进行交换,浸出液中的阴离子氟、硅、磷等基本不被萃取;利用阳离子在P204中的萃取顺序,将铁还原成二价铁,并在还原气氛中减少铝铁与铍同萃机会。同时高氟铍矿石中的氟与铝的络合作用可抑制铝的萃取,萃入有机相中的铝铁经洗涤后基本可除去。洗后的有机相经反萃、水解沉淀、煅烧得到合格的工业氧化铍。     

Effect of the conditions of REM microalloying of steel on the corrosion activity of nonmetallic inclusions

Experimental heats of low-alloy steel are performed under various conditions of rare-earth metal microalloying and aluminum and calcium deoxidation. Electron-probe microanalysis of nonmetallic inclusions and a metallographic investigation of a metal are used to show that, when interacting with water, nonmetallic cerium oxide inclusions do not form hydrates and, correspondingly, are not aggressive. When aluminum, calcium, and cerium additions are sequentially introduced into a melt, a continuous cerium oxide shell forms on calcium aluminates, protects corrosive nonmetallic inclusions against interaction with water, and weakens local metal corrosion.     

钒和铝在含钒页岩草酸浸出液中的赋存状态研究

以某含钒页岩草酸浸出液为对象,研究了钒和铝在含钒页岩草酸浸出液中的赋存状态。首先采用Medusa软件初步确定了钒和铝在草酸体系中的存在形式,然后对钒和铝的负载有机相分别进行红外光谱和质谱研究。结果表明:钒负载有机相萃合物化学式为[(R_4N)_2·VO(C_2O_4)_2],铝负载有机相萃合物的化学式分别为[(R_4N)·Al(C_2O_4)_2]和[(R4N)3·Al(C_2O_4)_3],因此可以确定含钒页岩草酸浸出液中钒主要以VO(C_2O_4)_2~(2-)络合阴离子存在,而铝主要以Al(C_2O_4)_2~-和Al(C_2O_4)_3~(3-)形式同时存在。     

Fabrication of Metallic Powders for Energy-Intensive Combustible Compositions by Mechanochemical Treatment: 1. Peculiarities of the Structure and State of Aluminum Powder Particles Formed by Mechanochemical Treatment

The morphology, dispersion, structure, and average particle size of aluminum powders after mechanochemical treatment with different organic modifiers (graphite, stearic acid, and polyvinyl alcohol) are investigated by electron force microscopy, X-ray phase analysis, IR spectroscopy, EDX, and granulometric analysis, which show significant changes in the particle surface layer. It is stated that the mechanochemical treatment of aluminum with organic additives leads to the partial reduction of the surface oxide layer and several types of active centers able to enter chemical reactions when using these composites in the composition of various combustible mixtures are formed. It is found that upon an increase in the content of modifiers, i.e., graphite and polyvinyl alcohol, in the composite with these additives, the activity of aluminum increases. The increment of the activity index falls with an increase in the content of stearic acid in the Al composite. This may be because a dense encapsulating layer poorly soluble in alkali is formed when grinding the Al–C1₇H₃₅COOH mixture with a large amount of stearic acid (more than 5%). Both the accumulation and redistribution of defects over the particle bulk, an increase in amount of active aluminum, and the formation of active centers and the encapsulating layer based on organic modifiers occur during the mechanical action in powders of the compositions under study.     

Formation mechanism of micro emulsion on aluminum and lanthanum extraction in P507-HCl system

P507 solvent extraction is the main method to separate and purify the rare earth products. The emulsification may be caused by the impurities in process of extracting rare earths, and these result in huge economic loss and decrease the quality of rare earth products. In recent researches, the extractant was prone to emulsification, and aluminum content of rare earth products also increased, while aluminum concentration of feed was higher. Pointing to this problem, the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy, and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al. Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion. The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted. The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L. If the extraction capacity of Al exceeded 5 g/L, it formed W/O of ME (micro emulsion), leading to form emulsion of the organic phase. When Al concentration of feed was less than 1 g/L, the aqueous phase would form O/W of ME. If aluminum was extracted by saponification P507 firstly, then the the organic phase loading aluminum extracted rare earth continually, the organic and aqueous phase formed emulsification easily.     

宽厚板立轧非均匀塑性变形机制

摘要：为探索高碳硅镇静钢中失效夹杂物的检测方法,通过大量分析切割钢丝拉拔断口明确了失效夹杂物类型,同时利用失效指数验证金相观察法、电镜分析法、极值统计法、电解法、盘条拉伸法等评价夹杂物的有效性。结果表明,以帘线钢、切割钢丝用钢为代表的高洁净度高碳硅镇静钢,失效夹杂物以高铝夹杂物为主,尺寸集中在10～40μm。断口分析是失效夹杂物的最直接评价方法,但耗时长。金相制样法评价失效夹杂物往往与实物质量不符。有机溶物电解法可以用来分析冶炼过程高铝夹杂物变化,为失效夹杂物控制提供方向。未时效盘条拉伸实验,可快速检测出高碳钢盘条中大尺寸夹杂物。     

Formation mechanism of micro emulsion on aluminum and lanthanum extraction in P507-HCl system

P507 solvent extraction is the main method to separate and purify the rare earth products.The emulsification may be caused by the impurities in process of extracting rare earths,and these result in huge economic loss and decrease the quality of rare earth products.In recent researches,the extractant was prone to emulsification,and aluminum content of rare earth products also increased,while aluminum concentration of feed was higher.Pointing to this problem,the structural change of saponification P507 extracting aluminum and lanthanum was investigated by infrared spectroscopy,and the results showed that Al ions exchanged with H of P-O-H to become P-O-Al.Because aluminum held the characteristic of hydrophilic after extracted in the form of hydroxyl polymer ions and this provided conditions for the formation of micro emulsion.The organic phase and aqueous phase were investigated by polarizing microscope after aluminum was extracted.The results showed that the organic phase was clear when the extraction capacity of Al was less than 5 g/L.If the extraction capacity of Al exceeded 5 g/L,it formed W/O of ME(micro emulsion),leading to form emulsion of the organic phase.When Al concentration of feed was less than 1 g/L,the aqueous phase would form O/W of ME.If aluminum was extracted by saponification P507 firstly,then the the organic phase loading aluminum extracted rare earth continually,the organic and aqueous phase formed emulsification easily.     

240#新型环烷酸萃取铝的研究

探讨了有机相皂化值、氯化铝溶液起始pH、萃取温度、萃取时间、相比及环烷酸浓度对240#新型环烷酸萃铝饱和容量的影响及损失率情况.实验结果表明,在有机相组成为20％环烷酸+20％异辛醇+60％磺化煤油(有机相酸值为0.75 mol·L-1),皂化值0.05～0.15 mol·L-1,萃取温度25℃,萃取时间60 min,...